Test Your Knowledge- Human Eye and the Colorful World Quiz
The quiz is provided at the bottom of the article. Before you attempt the quiz, I request you to go through the summary of the chapter given below.
Human Eye and The Colourful World – Summary (Class 10)
1. Structure of the Human Eye
- Cornea: Transparent front part that bends (refracts) light entering the eye.
- Aqueous Humour: Clear liquid behind cornea that keeps the eye in shape and provides nutrients.
- Iris: Colored part of the eye that controls the size of the pupil.
- Pupil: Opening through which light enters the eye.
- Lens: Convex, flexible lens that focuses light on the retina.
- Ciliary Muscles: Help change lens shape for focusing on near or far objects (accommodation).
- Retina: Inner layer with light-sensitive cells (rods & cones) where the image forms.
- Optic Nerve: Sends the image information to the brain.
2. Working of the Eye
- The lens forms a real, inverted image on the retina.
- Ciliary muscles adjust lens thickness for focusing at different distances – this is called accommodation.
- Near Point (Least Distance of Distinct Vision): 25 cm for a normal eye.
- Far Point: Infinity for a normal eye.
3. Common Defects of Vision
- Myopia (Short-sightedness): Cannot see far objects clearly – corrected with concave lens.
- Hypermetropia (Long-sightedness): Cannot see near objects clearly – corrected with convex lens.
- Presbyopia: Age-related difficulty in seeing near objects – corrected with bifocal lens.
- Cataract: Cloudy lens causing blurred vision – treated by surgery.
4. Refraction of Light Through Prism
- Light bends twice while passing through a prism (on entering and leaving).
- This causes dispersion – splitting of white light into seven colors (VIBGYOR).
- Red light bends the least, violet light bends the most.
5. Formation of Rainbow
- Raindrops act like tiny prisms.
- Sunlight refracts, reflects inside the drop, and refracts again while leaving.
- This creates a spectrum of colors which we see as a rainbow.
6. Atmospheric Refraction Phenomena
- Twinkling of Stars: Caused by atmospheric refraction of starlight.
- Apparent Sunrise and Sunset: The sun appears earlier at sunrise and later at sunset because its light bends in the atmosphere.
7. Scattering of Light
- Scattering depends on wavelength – shorter wavelengths scatter more.
- Blue Sky: Blue light scatters most, so the sky appears blue.
- Red Sun at Sunrise/Sunset: Blue light scatters away on the longer path, leaving red/orange light visible.
Check Your Progress, Lets see How much you learnt!
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